1. Field of the Invention
The present invention relates to an exhaust device for a work vehicle provided with an exhaust pipe for guiding exhaust to the exterior of the vehicle body.
2. Description of the Related Art
Known exhaust devices for a work vehicle such as that mentioned above include the following.
Specifically, Japanese Patent 3799405 discloses the following exhaust device for a work vehicle. Specifically, this exhaust device for a work vehicle is configured so that: an insulating pipe is externally fitted on the outside of an exhaust guide pipe into which exhaust from an engine is introduced; a cooling pipe is externally fitted in turn on the outside of the insulating pipe; heat in the innermost exhaust guide pipe is insulated by the insulating pipe at an intermediate position; and external air entering in a gap with respect to the outermost cooling pipe having a vent hole positioned on the outside of the insulating pipe cools the insulating pipe and prevents exhaust heat from being transmitted to the outside of the cooling pipe (e.g., see paragraphs 0016, 0025 and FIGS. 2, 3, and 13).
JP-A 07-71249 discloses the following exhaust device for a work vehicle. Specifically, this exhaust device for a work vehicle is configured so that: an exhaust guide pipe into which exhaust from the engine is introduced comprises an upstream-side guide pipe and a downstream-side guide pipe located to the front and to the rear in the direction of exhaust flow; and an ejector section provided between the upstream-side guide pipe and the downstream-side guide pipe causes external air to mix with the exhaust in the downstream-side guide pipe by means of an ejector effect accompanying the inflow of exhaust from the upstream-side guide pipe to the downstream-side guide pipe. The outside of the downstream-side guide pipe is covered by an external protective pipe for insulation (e.g., paragraphs 0020, 0028, FIGS. 4, 5, and 6).